Zack Williams | e940c7a | 2019-08-21 14:25:39 -0700 | [diff] [blame] | 1 | // Copyright 2018 The Go Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
David K. Bainbridge | bd6b288 | 2021-08-26 13:31:02 +0000 | [diff] [blame] | 5 | //go:build freebsd || netbsd |
Zack Williams | e940c7a | 2019-08-21 14:25:39 -0700 | [diff] [blame] | 6 | // +build freebsd netbsd |
| 7 | |
| 8 | package unix |
| 9 | |
| 10 | import ( |
| 11 | "strings" |
| 12 | "unsafe" |
| 13 | ) |
| 14 | |
| 15 | // Derive extattr namespace and attribute name |
| 16 | |
| 17 | func xattrnamespace(fullattr string) (ns int, attr string, err error) { |
| 18 | s := strings.IndexByte(fullattr, '.') |
| 19 | if s == -1 { |
| 20 | return -1, "", ENOATTR |
| 21 | } |
| 22 | |
| 23 | namespace := fullattr[0:s] |
| 24 | attr = fullattr[s+1:] |
| 25 | |
| 26 | switch namespace { |
| 27 | case "user": |
| 28 | return EXTATTR_NAMESPACE_USER, attr, nil |
| 29 | case "system": |
| 30 | return EXTATTR_NAMESPACE_SYSTEM, attr, nil |
| 31 | default: |
| 32 | return -1, "", ENOATTR |
| 33 | } |
| 34 | } |
| 35 | |
| 36 | func initxattrdest(dest []byte, idx int) (d unsafe.Pointer) { |
| 37 | if len(dest) > idx { |
| 38 | return unsafe.Pointer(&dest[idx]) |
| 39 | } else { |
| 40 | return unsafe.Pointer(_zero) |
| 41 | } |
| 42 | } |
| 43 | |
| 44 | // FreeBSD and NetBSD implement their own syscalls to handle extended attributes |
| 45 | |
| 46 | func Getxattr(file string, attr string, dest []byte) (sz int, err error) { |
| 47 | d := initxattrdest(dest, 0) |
| 48 | destsize := len(dest) |
| 49 | |
| 50 | nsid, a, err := xattrnamespace(attr) |
| 51 | if err != nil { |
| 52 | return -1, err |
| 53 | } |
| 54 | |
| 55 | return ExtattrGetFile(file, nsid, a, uintptr(d), destsize) |
| 56 | } |
| 57 | |
| 58 | func Fgetxattr(fd int, attr string, dest []byte) (sz int, err error) { |
| 59 | d := initxattrdest(dest, 0) |
| 60 | destsize := len(dest) |
| 61 | |
| 62 | nsid, a, err := xattrnamespace(attr) |
| 63 | if err != nil { |
| 64 | return -1, err |
| 65 | } |
| 66 | |
| 67 | return ExtattrGetFd(fd, nsid, a, uintptr(d), destsize) |
| 68 | } |
| 69 | |
| 70 | func Lgetxattr(link string, attr string, dest []byte) (sz int, err error) { |
| 71 | d := initxattrdest(dest, 0) |
| 72 | destsize := len(dest) |
| 73 | |
| 74 | nsid, a, err := xattrnamespace(attr) |
| 75 | if err != nil { |
| 76 | return -1, err |
| 77 | } |
| 78 | |
| 79 | return ExtattrGetLink(link, nsid, a, uintptr(d), destsize) |
| 80 | } |
| 81 | |
| 82 | // flags are unused on FreeBSD |
| 83 | |
| 84 | func Fsetxattr(fd int, attr string, data []byte, flags int) (err error) { |
| 85 | var d unsafe.Pointer |
| 86 | if len(data) > 0 { |
| 87 | d = unsafe.Pointer(&data[0]) |
| 88 | } |
| 89 | datasiz := len(data) |
| 90 | |
| 91 | nsid, a, err := xattrnamespace(attr) |
| 92 | if err != nil { |
| 93 | return |
| 94 | } |
| 95 | |
| 96 | _, err = ExtattrSetFd(fd, nsid, a, uintptr(d), datasiz) |
| 97 | return |
| 98 | } |
| 99 | |
| 100 | func Setxattr(file string, attr string, data []byte, flags int) (err error) { |
| 101 | var d unsafe.Pointer |
| 102 | if len(data) > 0 { |
| 103 | d = unsafe.Pointer(&data[0]) |
| 104 | } |
| 105 | datasiz := len(data) |
| 106 | |
| 107 | nsid, a, err := xattrnamespace(attr) |
| 108 | if err != nil { |
| 109 | return |
| 110 | } |
| 111 | |
| 112 | _, err = ExtattrSetFile(file, nsid, a, uintptr(d), datasiz) |
| 113 | return |
| 114 | } |
| 115 | |
| 116 | func Lsetxattr(link string, attr string, data []byte, flags int) (err error) { |
| 117 | var d unsafe.Pointer |
| 118 | if len(data) > 0 { |
| 119 | d = unsafe.Pointer(&data[0]) |
| 120 | } |
| 121 | datasiz := len(data) |
| 122 | |
| 123 | nsid, a, err := xattrnamespace(attr) |
| 124 | if err != nil { |
| 125 | return |
| 126 | } |
| 127 | |
| 128 | _, err = ExtattrSetLink(link, nsid, a, uintptr(d), datasiz) |
| 129 | return |
| 130 | } |
| 131 | |
| 132 | func Removexattr(file string, attr string) (err error) { |
| 133 | nsid, a, err := xattrnamespace(attr) |
| 134 | if err != nil { |
| 135 | return |
| 136 | } |
| 137 | |
| 138 | err = ExtattrDeleteFile(file, nsid, a) |
| 139 | return |
| 140 | } |
| 141 | |
| 142 | func Fremovexattr(fd int, attr string) (err error) { |
| 143 | nsid, a, err := xattrnamespace(attr) |
| 144 | if err != nil { |
| 145 | return |
| 146 | } |
| 147 | |
| 148 | err = ExtattrDeleteFd(fd, nsid, a) |
| 149 | return |
| 150 | } |
| 151 | |
| 152 | func Lremovexattr(link string, attr string) (err error) { |
| 153 | nsid, a, err := xattrnamespace(attr) |
| 154 | if err != nil { |
| 155 | return |
| 156 | } |
| 157 | |
| 158 | err = ExtattrDeleteLink(link, nsid, a) |
| 159 | return |
| 160 | } |
| 161 | |
| 162 | func Listxattr(file string, dest []byte) (sz int, err error) { |
| 163 | d := initxattrdest(dest, 0) |
| 164 | destsiz := len(dest) |
| 165 | |
| 166 | // FreeBSD won't allow you to list xattrs from multiple namespaces |
| 167 | s := 0 |
| 168 | for _, nsid := range [...]int{EXTATTR_NAMESPACE_USER, EXTATTR_NAMESPACE_SYSTEM} { |
| 169 | stmp, e := ExtattrListFile(file, nsid, uintptr(d), destsiz) |
| 170 | |
| 171 | /* Errors accessing system attrs are ignored so that |
| 172 | * we can implement the Linux-like behavior of omitting errors that |
| 173 | * we don't have read permissions on |
| 174 | * |
| 175 | * Linux will still error if we ask for user attributes on a file that |
| 176 | * we don't have read permissions on, so don't ignore those errors |
| 177 | */ |
| 178 | if e != nil && e == EPERM && nsid != EXTATTR_NAMESPACE_USER { |
| 179 | continue |
| 180 | } else if e != nil { |
| 181 | return s, e |
| 182 | } |
| 183 | |
| 184 | s += stmp |
| 185 | destsiz -= s |
| 186 | if destsiz < 0 { |
| 187 | destsiz = 0 |
| 188 | } |
| 189 | d = initxattrdest(dest, s) |
| 190 | } |
| 191 | |
| 192 | return s, nil |
| 193 | } |
| 194 | |
| 195 | func Flistxattr(fd int, dest []byte) (sz int, err error) { |
| 196 | d := initxattrdest(dest, 0) |
| 197 | destsiz := len(dest) |
| 198 | |
| 199 | s := 0 |
| 200 | for _, nsid := range [...]int{EXTATTR_NAMESPACE_USER, EXTATTR_NAMESPACE_SYSTEM} { |
| 201 | stmp, e := ExtattrListFd(fd, nsid, uintptr(d), destsiz) |
| 202 | if e != nil && e == EPERM && nsid != EXTATTR_NAMESPACE_USER { |
| 203 | continue |
| 204 | } else if e != nil { |
| 205 | return s, e |
| 206 | } |
| 207 | |
| 208 | s += stmp |
| 209 | destsiz -= s |
| 210 | if destsiz < 0 { |
| 211 | destsiz = 0 |
| 212 | } |
| 213 | d = initxattrdest(dest, s) |
| 214 | } |
| 215 | |
| 216 | return s, nil |
| 217 | } |
| 218 | |
| 219 | func Llistxattr(link string, dest []byte) (sz int, err error) { |
| 220 | d := initxattrdest(dest, 0) |
| 221 | destsiz := len(dest) |
| 222 | |
| 223 | s := 0 |
| 224 | for _, nsid := range [...]int{EXTATTR_NAMESPACE_USER, EXTATTR_NAMESPACE_SYSTEM} { |
| 225 | stmp, e := ExtattrListLink(link, nsid, uintptr(d), destsiz) |
| 226 | if e != nil && e == EPERM && nsid != EXTATTR_NAMESPACE_USER { |
| 227 | continue |
| 228 | } else if e != nil { |
| 229 | return s, e |
| 230 | } |
| 231 | |
| 232 | s += stmp |
| 233 | destsiz -= s |
| 234 | if destsiz < 0 { |
| 235 | destsiz = 0 |
| 236 | } |
| 237 | d = initxattrdest(dest, s) |
| 238 | } |
| 239 | |
| 240 | return s, nil |
| 241 | } |